Enhancing long-term frequency stability of a single-mode optoelectronic oscillator based on phase conjugation.

We propose and experimentally demonstrate what we believe to be a novel single-mode optoelectronic oscillator (OEO) with low frequency drift based on phase conjugation. The long-term frequency stabilization of the OEO is achieved by using photonic microwave phase-conjugate passive compensation. Besides, since there happens to be a nonlinear coupled double loop structure in the OEO, single-mode oscillation can be achieved. The experimental results show that the side mode suppression ratio (SMSR) of the radio frequency (RF) signal from the OEO at 9.93 GHz is enhanced from 5 dB to 68 dB after side mode suppression, and the maximum frequency drift within 600 s reduced from 1.51 ppm to 0.04 ppm, optimized by a factor of about 40. The OEO has a simple structure, no external injection, and the phase noise is not limited by the injected signal.

Direct and positive regulation of Caenorhabditis elegans bed-3 by PRDM1/BLIMP1 ortholog BLMP-1.

Caenorhabditis elegans BLMP-1 is the homolog of mammalian PRDM1/BLIMP1 transcriptional repressor and a component of the heterochronic pathway regulating developmental timing. We found that BLMP-1 positively and directly regulates the bed-3 gene required for vulval cell division and molting. blmp-1 mutation or RNAi reduces bed-3 reporter expression and causes phenotype similar to bed-3 mutations. We mapped an enhancer element responsible for bed-3 expression in the vulva and the hypodermis to a 200 bp region in the third intron. Using EMSA, we identified BLMP-1 binding sites within this region. Mutating these sites abolished both in vitro BLMP-1 binding and in vivo enhancer activity. Thus, BLMP-1 directly and positively regulates bed-3 transcription, connecting the heterochronic pathway to regulation of vulval cell division and molting. Recently, C. elegans blmp-1 was found to act as a transcriptional repressor. Thus, C. elegans BLMP-1 acts as a transcriptional activator or a repressor depending on the context.

Tunable dual frequency optoelectronic oscillator with low intermodulation based on dual-parallel Mach-Zehnder modulator.

A tunable dual-frequency optoelectronic oscillator (OEO) based on dual-parallel Mach-Zehnder modulator (DPMZM) with low intermodulation is proposed and experimentally demonstrated. Two tunable electronic band-pass filters are used to select the oscillation modes of the two oscillating frequencies to achieve tunable dual-frequency OEO (TDF-OEO). Each of the two selected modes are modulated onto one sub-modulator of the DPMZM. By choosing proper bias conditions of the DPMZM, the intermodulation components generated by the dual-frequencies are suppressed. The tuning range of the TDF-OEO is from 1 GHz to 15 GHz in the experiment. We also discussed and experimentally demonstrated the tuning limitation of this dual frequency system.

Promoter analysis of the sweet potato ADP-glucose pyrophosphorylase gene IbAGP1 in Nicotiana tabacum.

KEY MESSAGE: The IbAGP1 gene of sweet potato ( Ipomoea batatas ) encodes the sucrose-inducible small subunit of ADP-glucose pyrophosphorylase. Through expression analysis of 5'-truncations and synthetic forms of the IbAGP1 promoter in transgenic tobacco, we show that SURE-Like elements and W-box elements of the promoter contribute to the sucrose inducibility of this gene. Sweet potato (Ipomoea batatas) contains two genes (IbAGP1 and IbAGP2) encoding the catalytically active small subunits of ADP-glucose pyrophosphorylase, an enzyme with an important role in regulating starch synthesis in higher plants. Previous studies have shown that IbAGP1 is expressed in the storage roots, leaves, and stem tissues of sweet potato, and its transcript is strongly induced by applying sucrose exogenously to detached leaves. To investigate the tissue-specific expression of the IbAGP1 promoter, a series of 5'-truncated promoters extending from bases -1913, -1598, -1298, -1053, -716, and -286 to base +75 were used to drive the expression of the ß-glucuronidase reporter gene (GUS) in tobacco plants (Nicotiana tabacum). Histochemical and fluorometric GUS assays showed that (1) GUS expression driven by the longest fragment (1989 bp) of the IbAGP1 promoter was detected in vegetative tissues (roots, stems, leaves), (2) fragments extending to -1053 or beyond retained strong GUS expression in roots, stems, and leaves, whereas further 5'-deletions resulted in considerable reduction in GUS activity, and (3) the series of 5'-truncated promoters responded differently to exogenously applied sucrose. The 1989-bp IbAGP1 promoter contains five sequences (two AATAAAA, one AATAAAAAA, and two AATAAATAAA) that are similar to sucrose-responsive elements (SURE). These SURE-Like sequences are found at nucleotide positions -1273, -1239, -681, -610, and -189. Moreover, putative W-box elements are found at positions -1985, -1434, -750, and -578. Synthetic promoters containing tandem repeats of the 4X SURE-Like or 4X W-box upstream from a minimal CaMV35S promoter-GUS fusion showed significant expression in transgenic tobacco in response to exogenous sucrose. These results show that SURE-Like elements and W-box elements of the IbAGP1 promoter contribute to the sucrose inducibility of this gene.

One-stone, two birds: One step regeneration of discarded copper foil in zinc battery for dendrite-free lithium deposition current collector.

The ever-growing requirement for electrochemical energy storage has exacerbated the production of spent batteries, and the recycling of valuable battery components has recently received a remarkable attention. Among all battery components, copper foil is widely utilized as a current collector for stable zinc platting and stripping in zinc metal batteries (ZMBs) due to the perfect lattice matching of between metal copper and zinc, which is accompanied by the formation of multiple copper-zinc alloy components during the cycling process. Herein, a novel "two birds with one-stone" strategy through a one simple heat treatment step to revive the discarded copper foil in zinc metal battery is reported to further obtain a lithiophilic current collector (CuxZny-Cu) with multiple copper-zinc alloy components on the surface of the discarded copper foil. Such revived CuxZny-Cu current collector greatly reduces the lithium nucleation overpotential and realizes uniform lithium deposition and further inhibits lithium dendrites growth. The formed multiple CuxZny alloy phases on the surface of discarded copper foil exhibit a low Li nucleation overpotential of only 15 mV at 0.5 mA cm-2 for the first cycle. Moreover, such a CuxZny-Cu current collector could achieve stable cycle for 220 cycles at 0.5 mA cm-2 and 110 cycles at 1 mA cm-2 with a Li plating capacity of 1 mAh cm-2. Theoretical calculations indicate that, compared with pure Cu foil, the formed multiple alloy components of CuZn5, CuZn8, Cu0.61Zn0.39 and CuZn have low adsorption energy of -2.17, -2.55, -2.16 and -2.35 eV with lithium atoms, respectively, which result in reduced lithium nucleation overpotential. The full cell composed of CuxZny alloy current collector with deposition of 5 mAh cm-2 metal Li anode coupled with LiFePO4 (LFP) cathode exhibits a reversible capacity of 125.6 mAh/g after 110 cycles at a current of 0.5 C with capacity retention of 85.1 %. This work proposed a promising strategy to regenerate the discarded copper foil in rechargeable batteries.

Which Exercise Approaches Work for Relieving Cancer-Related Fatigue? A Network Meta-analysis.

OBJECTIVE: To determine the most effective exercise modalities for managing cancer-related fatigue during and after cancer treatment. DESIGN: Network meta-analysis (NMA) of randomized controlled trials. LITERATURE SEARCH: Seven electronic databases were systematically searched from inception to January 2022. STUDY SELECTION CRITERIA: Randomized controlled trials testing the effects of exercise on relieving cancer-related fatigue in adult patients with cancer. DATA SYNTHESIS: An NMA of 56 studies was conducted, and the PRISMA-NMA guidelines were followed when reporting results. To determine the most effective interventions, the surface under the cumulative ranking curve (SUCRA) value was calculated for each exercise modality. RESULTS: Combined aerobic and resistance exercise (standardized mean difference [SMD], 1.57; credible interval [CrI], 1.03-2.10), yoga (SMD, 1.02; CrI: 0.44, 1.60), and regular physical activity (SMD, 1.07; CrI: 0.21, 1.92) could significantly alleviate cancer-related fatigue compared to control groups (usual care, wait-list, and regular physical activity). Combined aerobic and resistance exercise (SUCRA, 97.2%) had the highest probability of efficacy, followed by yoga (SUCRA, 75.5%) and regular physical activity (SUCRA, 74.1%). During cancer treatment, combined aerobic and resistance exercise (SUCRA, 94.5%) ranked first in efficacy, followed by regular physical activity (SUCRA, 82.1%) and yoga (SUCRA, 73.8%). After cancer treatment, only combined aerobic and resistance exercise (SMD, 0.99; CrI: 0.13, 1.84) had a significant effect on cancer-related fatigue. CONCLUSION: Combined aerobic and resistance exercise, yoga, and regular physical activity were the most effective exercise modalities for alleviating cancer-related fatigue. Combined aerobic and resistance exercise is recommended during and after cancer treatment. J Orthop Sports Phys Ther 2023;53(6):1-10. Epub: 23 March 2023. doi:10.2519/jospt.2023.11251.